Timing
It can seem that timing has a huge role to play in the way we raise our children as well. If you want to make your children think that you are some all-knowing and all-seeing human being, you can try this out. If you catch them doing something that they are not supposed to do, do not react.
Do not let them see you and just walk away, then later, for example at dinner, reprimand their actions and they will be confused as to how you know it was them. They may be afraid to do it at all ever again knowing that you can be anywhere at any time, watching them.